Part of the issue around transparency is that email inbox silos may be the wrong tool for a collaborative and productive tech company. In general, email is now being seen (as often remarked by ShowHN MVPs) as To Do lists, and in a tech shop, multiple people have an interest in that process. This results in unenforceable policies about To: vs Cc: and unwieldy threads you're never sure if you should delete the tail nes…
Maybe I'm just weird, but I do this pretty frequently (fire off quick instructions/reminders with "TODO:" prepended); after all, there's very little besides email that I care enough about to check frequently enough for any action items I assign to myself to matter.
I understand and agree with the idea behind the "Show HN" projects you mention, but as a potential user, at the end of the day all I really care about is that my personal system/workflow works and helps me get stuff done, not how structured or semantically beautiful my data is. The last thing I need is yet another application/service to demand time/attention from my day.
(On a similar note, I've never been able to commit myself to a well-organised file structure with meaningful nested directories, an indexing system, and so forth, when a flat directory holding tens of thousands of files + ls and whatever regexes has Just Worked for me for years, despite not being pretty.)